James l



JAMES n. PLiMP'roN, or WES'rFIELD, MASSACHUSETTS.

MACHINERY FOR GRINIDING CONICAL-EDGED KNIVES,l 1

Specification of Letters Patent No. 8,926, dated May 4, 1852.

To all whom 'it may concern:

Be it known that I, JAMES L. PLIMr'roN,

` of Westfield, in the county of Hampden and State of Massachusetts, have invented certain new and useful improvements in machines for grinding curved knives or knives which are intended to be bent or twisted of a spiral `form, asthe spiral knives of strawcutters, &c.; and I do hereby declare that the following isa full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which;

Figures l, and 2, are elevations of opposite sides of the machine. Fig. 3, is a plan of the same. Fig. il, is a perspective view of the carriage which supports the table to which the knives or Vcutters are' secured. Fig. 5, is an inverted plan, or view of the under side of the table.

Similar letters of reference indicate corresponding parts in each" of the several lig- The nature of my invention consists, in an improved carriage and table for holding the knives, which admits of their being presented to the rotating periphery of the stone, so that `their edges may be ground at any bevel, without being caused to deviate from the required form, viz: that of an arc of a circle.

It further consists in an improved feedf ing motion, whereby the edge of the knife is caused to move toward the stone, asit (the stone) wears down by grinding; and whereby the speed of the travel of the edge across the stone, is always governed by the velocity of the `motion of the periphery of the stone, and any wear of the stone, and consequent decrease in the velocity of the motion of its periphery, causes the speed of i the feed motion to decrease in a correspondtion.

ing ratio. i

To enable others skilled in the art to make and use my invention, I will proceed to describe fully its construction and opera- A, A, A, (Figs. 1, 2 and 3,) is a strong frame of timber or other material,.of suitable form strength and dimensions to carry the working parts of thelmachinery.

B, represents the grindstone, whose aXis C, rests in bearings D, D, one on each side, on the frame A, A,1A. i

E, E,` (Figs. l and 2,) is a frame of cast iron or other suitable material, consisting of two 4short longitudinal bars resting on the top of the frame and united by a cross piece; it is capable of sliding (by the means to be hereinafter described) longitudinally on the frame.

F, (seen in Figs. 1, 2 and 3, but more distinctly in Fig. 4, where it is represented `detached `from the `machine) is a carriage, `made of castiron or other metal, presenting, when seen from above, the form of a cross, and having Journals or trunnions (a)e (a), at the ends of its arms (c), (c), which rest in bearings b, o, on the frame E, E; on l the front end of the carriage is an upright part (CZ), and behind the crossV arm c, 0, there is a standard Gr, whichV is `firmly secured `by bolting through, and carries a rail or way H, which is an arc of a circle. This rail or way H, is faced true on its `upper side, and supportsa table I, which is a Hat metal plate having guides f, f, f', f", on its under side tting to the edges of` the Vrail or way H, the back guides ff are flanged to prevent the table being thrown `off the way; on the top of the table are two clamps or dogs g, g, for holding the knife or cutter g, g, to be ground, which is represented by L, (Figs. 1, 2, and 3) having its edge hanging over the edge `of the table I; a rest z', adjusted by a screw Z, is secured in front of the upright part d, of the carriage, for thepurpose of supporting the edge of the knife and preventing vibration of the table; the carriage being hung on journals,

the back end of it is capable of being raised or lowered so as to present the table at any required angle to the periphery of the stone and to give any required bevel to the edge of the knife; an arc y', is attached under the back of the carriagewhich passes through a slot in the frame E, E, E, and is secured by a set screw 70, (see Fig. 3) for the purpose of holding the carriage in position; a

spindle r, passes through the arms c, c, and journals a, a, of the carriage, which are bored through to receive it; this spindle has an arm m, firmly secured on one end, and one m', on the other end both of equal length, in the ends of these arms are the `bearings of a spindle n, which carries an endless screw 0, (see Figs. 1 Vand3,) gearing into a toothed arc p, under the ltable I, the spindle n, carries a small pulley g, through which it receives motion; the arm m', is elongated below the spindle r, and carries a stud s, (Figs. 2, and 3), on which are a loose pulley t, and a smallerone both secured together, attached to the arm m, is a lever out of gear with the arc p.

u, by which the endless screw o, is thrown J, J, J, (rigs. i, 2, and a) is@ frame of cast yiron consisting of a bar resting across the top of the frame A,-A, A, having elbows and arms hanging "over each side; near the ends of the bar and nearly close to the top of the frame, two stro-ng rods of iron K, are bolted through and'secured by nuts, these rods rest on cleats, L, L, on the sides of 4the frame and have sockets M, M, at their ends, in which are right handed vfemale screws; spindles having right handed male screws N, N, at one end fit in the female screws in the above socket, and thev said spindles have also left handed male screws l, N', at the back of the right handed screws, these left handed screws t in corresponding female screws in overhanging ears O, O, of a frame P, P, P, vwhich is placed above the frame E, E, E, but allows the latter frame to slide freely below and rindependent of it, the spindle carrying the right and left handed screws have journals turned in them which fit in boXes Q;Q, secured to the sides of the main frame A A A, and carry at their outer ends worm wheels R, R; shoulders being formed on the spindles on each side of the boxes prevent any longitudinal motion of the spindles.

S, is a shaft hung in bearings T, T, secured under the end of the frame A, A, it carries endless screws V, V, gearing into the worm wheels R R, and it also carries a pulley V.

A frame consisting of -t-wo arms V, V, united by a barVV, is hung so as to swing between center screws, w, w, which are secured in Vthe overhanging arms of the frame J, J, J in the upper ends of the arms V, V, are `eyes which form the bearings for the journals of a shaft X, which carries a roller Y, fast upon it, and a disk Z, which is prevented from turning by a feather on the shaft; close to the disk Z, a loose pulley agis hung upon the shaft and rests against va shoulder, the end of the shaft is screwed and carries a nut y, between which and the disk is afspringing cruciform plate e; the nut can be screwed up so that the spring plate will cause the face of the disk to bear on the facex of the pulley so as to produce enough'frixction to allow -the pulley to be carried around by the revolution of the disk, when not held by other means; a lever l, hangs loosely on the shaft X, and carries at its end a Afixed spindle on which is a -loose pulleyA 2; aband 3, passes around the pulley a3, and Aaround the pulley V, on the shaft S, and the pulley 2, rests upon it, its

weight and that of the lever l, keeping the band tight and making the periphery of the roller Y, to bear always on the periphery of the grindstone, withjust a sufficient of friction to be driven around by t-he revoluupon the same end of the shaft a lever 5 hangs loosely. Upon the stud s', which carries the pulleys t, and 25 another lever 6, is hung; the levers 5, and 6, are jointed together by a pin or stud 7, and upon this pin two pulleys 8 and 9 both (secured to either) are hung so as to turn freely, l0 is a band running from the pulley 4, to the pulley 8. l1, isa band running from the pulley 9, to thepulley ,Qtlie pulleys 8 and 9, are hung in the levers 5 and 6, so that the bands will always be tight, notwithstanding the variation in the distance between the pulleys t, and if-c, is a band running from the pulley t, to the pulley g, on the spindle n,

E, a shoulder is made on each side of the journal so to cause the frame E, E, E, to move back or forth as the screw 1s screwed y out or in. y

The operation is as follows: Rotary motion'is given to the grindstone by any convenient means; the carriage F, is set at any inclination according to the required bevel of the edge of the knife; and the frame E E E, is then moved forward by turning the screw12, so as to bring the knife up to the stone. The roller Y, receivinga rotary motion from the grindstone, upon which it always bears lgives motion to the shaft X, and the pulley 4E, upon the said shaft, communicates the motion through the band 10,'the pulleys 8, and 9, the bandr 1l the pulleys t,

and t, and the band e, running on the pul` ley g, to the spindle fn, this spindle by means of its endless screw 0, gearing into the toothed arc y? will move the table I, along the way H, taking the edge of the knife across the stone. As the table I, is a plane parallel with the face of the way H, and the knife lies flat o-n the table, it is obvious that each entire side of the knife moves in the same plane, 'at whatever angle the carriage' The wear of the stone 1s compensated for' in the following manner: Before starting the machinery the shaft S, is turned by a handle on the pulley Y, so as to cause the endless screws V, V, and worm wheels R, R, to turn the screw spindles N, N, N, N, in such a direction as to screw the right handled screws N, N, into the sockets M, M, of the rods K, K; the screws being prevented from moving longitudinally, will draw forward the frame J, J, until its front edge bears upon the periphery of the pulley sufficiently to prevent its being carried round by the friction of the disk Z, on its face; on any wear of the stone taking place the shaft X, will be drawn forward by the weight of the pulley 2, bearing on the band 3, and the pulley m, will be released from contact with the frame J, and commence rotating with the shaft X, giving motion through the band 3, and pulley V, to the shaft S; the endless screws on the said shaft S, operating on the worm wheels R, R, will turn the screwed spindles in such a direction that the screws N, N, shall draw the frame J, J, J, up again to the pulley m, and stop its revolution. While the screws N, N, draw up the frame J, J, J, those N, N', passing through the ears O, O, on the frame P, P, P, draw the said frame toward the stone, and this vframe being connected by the screw 12, to the frame E, E, E, draws it up also, and brings the knife closer to the stone; the screws N, N, and N, N, all being of an equal pitch it will be understood that the knife moves exactly the same distance toward the axis of the stone, as does the roller Y. The friction between the d-isk Z, and the pulley x, being well regulated `the knife may be made to accommodate itself to the slightest wear of the stone.

It will be observed that the feed motion which moves the knife across the stone being driven by the roller Y, (the wear of which is so slight as to be imperceptible) and the roller `being driven by the stone itself, that whatever is the diameter of the stone, and however it may wear down, the amount of feed is always governed by the velocity of the stones periphery and is in proportion to it.

The way I-I, may be any part of a circle, and the table I, long enough to carry any number of knives; and being mounted on the adjustable carriage F, will do its work correctly at any degree of Obliquity.

I am aware that different devices have been employedfor altering the position of knives so as to grindtheir edges of different bevels as for instance the machine invented by Silas Stevens in which the tilting motion is applied `to the knife alone in this the bevel of the edge of the knife cannot be altered without altering the form of the periphery of the knifes edge and it will not grind the ends of the knife the same bevel that it grinds the center of the knifes edge and the effect produced by his machine is entirely different from that of mine. I apply the tilting motion to the arm or carriage F (see Figs. l, 2 and 8) which sup' ports theway I-I on which the table I is moved and as the flat side of the knife is confined to the plane of the table I, which is parallel to the face of the way H it is obvious vthat the knifes edge when ground must be of the same bevel throughout its entire length and the form of the periphery of the knifes edge must be that of an arc of a circle at whatever inclination the arm F, may be placed by thus applying the tilting motion to the carriage instead of applying it to the knife alone I can give any desired bevel to the ground edge of the knife without producing any other variation, As the edges of the knives when ground twisted vand set upon the axis of a cylinder are required to cut a straight line it will readily be seen that the form given to the periphery of the knifes edge is a very essential point and a point upon which the perfect operation of the cylinder depends.

Having thus fully described the nature, construction, and operation of my invention I will now state what I claim as new therein and desire to secure by Letters Patent- 1. The combination of the curved way H and table I thereon-provided with appropriate automatic contrivances for traversing the latter along the former, with the carriage F on which they are both supported and which is provided with axis and screws or their equivalents to adjust said carriage F to any required angle with the horizon for the purposes herein fully described.

2. I claim operating the feed motion, or the motion for carrying the edge of the knife across the periphery of the stone, by means of a roller N, bearing on the periphery of the stone, in the manner and for the purposes herein fully set forth.

3. I claim connecting the carriage F, and the table I, which carry the knife, with the roller Y, receiving motion from the stone, by means of the combination of mechanism substantially as herein described, by which the motion of the roller toward the axis of the stone consequent upon the wear of the stone, will cause the knife or knives being ground, to follow the periphery of the stone, and thereby compensate for its wear, and preserve the required form of the edge or edges of the knives, viz: that of an arc of a circle as herein fully set forth.

In testimony whereof I have hereunto signed my name before two subscribing witmesses.

JAMES L. PLIMPTON. 

